1. Field of the Invention
The present invention relates to an elevator controlling apparatus which performs direct numerical control in correspondence with the divided time zones established by dividing a day into a substantially constant number of time zones, and particularly to an elevator controlling apparatus which is capable of optimizing divided time zones by statistically processing variation in the load (traffic) on an elevator for one day.
2. Description of Related Art
In recent years, elevator controlling apparatuses used for direct numeral control of a plurality of elevator cages have been capable of advanced control based on the arithmetic operation of a large quantity of information. For example, there are many elevator controlling apparatuses which are provided with a learning function to modify direct numeral control in accordance with traffic, which easily varies, by the statistical processing of the traffic in a day in a building.
It is generally known that the traffic in a building varies depending upon various factors such as the office-going time zone in the morning and the normal time zone in the daytime, the direction of movement of an elevator and so forth. An elevator controlling apparatus has been thus proposed in which the time of day is divided into a predetermined number of time zones, and statistical processing and the formation of control information are performed by using as a unit each of the divided time zones, as disclosed in Japanese Patent Laid-Open No. 58-113085. Although the predetermined number of time zones into which a day is divided depends upon the performance of the processor used and the memory capacity of learning means and operation controlling means, it is generally about 24 or 36.
However, in the aforementioned controlling apparatus disclosed in the publication, divided time zones are established so that the traffic values in all the divided time zones are equal to each other. Namely, each of divided time zones having low traffic values is set to be long, and each of divided time zones having high traffic values is set to be short. Thus, the actual time at which traffic value in a building changes does not always agree with the time on the border between two divided time zones, and the characteristics of the traffic in the building cannot be correctly reflected.
As described above, conventional elevator controlling apparatuses have the problem that, since the divided time zones are determined so that the values of traffic in the time zones are equal to each other, the actual characteristics of traffic in a building cannot be reflected, and direct numeral control cannot be properly effected.